[Idiot211]

Not a payroll human but someone who lives in the UK.

It does not, we have various brackets that you fall into as your income rises.

- No income tax is paid on the first £12,500 of your earnings - 20% on everything between £12,500 and £50,000 - 40% on anything between £50,000 and £150,000 - 45% on anything over £150,000

The way that HMRC likes to figure it out is that you take the salary of the person in question, and then you take into account all of the above bracketing plus more little gotchas. And spread their tax over the course of the whole year as evenly as possible.

This gets more complex when you change jobs or get a new salary midway through the tax year and then payroll software has to account for that and try and even out all the payments for the rest of the year.

Hopefully that makes some sense!